That still means “I get to decide”; it’s still a subjective decision. The answer here should be objective, not subjective.
No – Paul taught that there were folks who honestly thought that the Holy Spirit was leading them, were wrong.
Paul offered correction to those who were wrong. Does that mean that he merely left them to their own personal feelings about God or the Holy Spirit, or does it mean that he said “hey – you’re mistaken; here’s what God is asking of you”…?